Use of magnetic carbon composites from renewable resource materials for oil spill clean up and recovery

ABSTRACT

A method for separating a liquid hydrocarbon material from a body of water. In one embodiment, the method includes the steps of mixing a plurality of magnetic carbon-metal nanocomposites with a liquid hydrocarbon material dispersed in a body of water to allow the plurality of magnetic carbon-metal nanocomposites each to be adhered by an amount of the liquid hydrocarbon material to form a mixture, applying a magnetic force to the mixture to attract the plurality of magnetic carbon-metal nanocomposites each adhered by an amount of the liquid hydrocarbon material, and removing said plurality of magnetic carbon-metal nanocomposites each adhered by an amount of the liquid hydrocarbon material from said body of water while maintaining the applied magnetic force, wherein the plurality of magnetic carbon-metal nanocomposites is formed by subjecting one or more metal lignosulfonates or metal salts to microwave radiation, in presence of lignin/derivatives either in presence of alkali or a microwave absorbing material.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/487,323, filed on Jun. 18, 2009, still pending entitled“MICROWAVE-ASSISTED SYNTHESIS OF CARBON AND CARBON-METAL COMPOSITES FROMLIGNIN, TANNIN AND ASPHALT DERIVATIVES AND APPLICATIONS OF SAME” by TitoViswanathan, which is incorporated herein by reference in its entiretyand itself claims the benefit, pursuant to 35 U.S.C. §119(e), of U.S.provisional patent application Ser. No. 61/132,380, filed Jun. 18, 2008,entitled “MICROWAVE-ASSISTED SYNTHESIS OF CARBON AND CARBON-METALCOMPOSITES FROM LIGNIN, TANNIN AND ASPHALT DERIVATIVES,” by TitoViswanathan, which is incorporated herein by reference in its entirety.This application also claims the benefit, pursuant to 35 U.S.C. 119(e),of U.S. provisional patent application Ser. No. 61/211,826 filed Apr. 3,2009, entitled “USE OF MAGNETIC CARBON COMPOSITES FROM RENEWABLERESOURCE MATERIALS FOR OIL SPILL CLEAN UP,” by Tito Viswanathan.

STATEMENT OF FEDERALLY-SPONSORED RESEARCH

The present invention was made with Government support under Grant No.DEFC 36-06G086072 awarded by U.S. Department of Energy (DOE). Thegovernment has certain rights in the invention.

This application relates to U.S. Pat. No. 8,167,973, filed Jun. 18,2009, entitled “MICROWAVE-ASSISTED SYNTHESIS OF CARBON AND CARBON-METALCOMPOSITES FROM LIGNIN, TANNIN AND ASPHALT DERIVATIVES,” by TitoViswanathan.

Some references, which may include patents, patent applications andvarious publications, are cited in a reference list and discussed in thedescription of this invention. The citation and/or discussion of suchreferences is provided merely to clarify the description of the presentinvention and is not an admission that any such reference is “prior art”to the invention described herein. All references cited and discussed inthis specification are incorporated herein by reference in theirentireties and to the same extent as if each reference was individuallyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to the field of separatingmixtures of water and oil, and oil spill clean up and recovery, inparticular, to separating mixtures of water and oil, and oil spill cleanup and recovery using magnetic carbon composites from renewable resourcematerials, and applications of same.

BACKGROUND

Using magnetic materials that can attract oil in the clean up ofpetroleum spills is not new. It is understood that U.S. Pat. No.7,303,679 discloses a method of recovering spilled hydrocarbon fluidsfrom a body of water utilizing the increased oleophilic properties ofreacted iron particles suspended in a magnetorheological (MR) fluid. Theiron particles normally used to create MR fluids, are reacted with anorganic compound containing an oleophilic chain end which attaches tothe surface of the iron, prior to suspension in a liquid vehicle such asan organic oil. The reacted iron particles in the MR fluid are thenapplied to and mixed with a hydrocarbon spill on a body of water such asan oil spill in water, whereby subsequent exposure to a significantmagnetic field provides for subsequent recovery of both the reactedmagnetic particles and the hydrocarbon spill. Other methods may alsoexist. However, such a synthetic procedure may be considered as tedious,expensive, and time consuming. Moreover, use of organic solvents may notbe considered environmentally friendly. Thus, currently there is not anaffordable yet efficient product available for oil spill clean up andrecovery.

Therefore, a heretofore unaddressed need exists in the art to addressthe aforementioned deficiencies and inadequacies.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a method for separating aliquid hydrocarbon material from a body of water. In one embodiment, themethod includes the steps of:

mixing a plurality of magnetic carbon-metal nanocomposites with a liquidhydrocarbon material dispersed in a body of water to allow the pluralityof magnetic carbon-metal nanocomposites each to be adhered by an amountof the liquid hydrocarbon material to form a mixture;

applying a magnetic force to the mixture to attract the plurality ofmagnetic carbon-metal nanocomposites each adhered by an amount of theliquid hydrocarbon material; and

removing said plurality of magnetic carbon-metal nanocomposites eachadhered by an amount of the liquid hydrocarbon material from said bodyof water while maintaining the applied magnetic force,

wherein the plurality of magnetic carbon-metal nanocomposites is formedby subjecting one or more metal lignosulfonates or metal salts tomicrowave radiation, in presence of lignin/derivatives either inpresence of alkali or a microwave absorbing material, for a period oftime effective to allow a plurality of carbon-metal nanocomposites to beformed.

In one embodiment, the microwave radiation has a frequency in the rangeof 900 MHz to 5.8 GHz.

In one embodiment, the microwave absorbing material comprises graphite,carbon black, or a combination of them.

The one or more metal lignosulfonates or metal salts each are magneticin their elemental form or in their oxide form. In one embodiment, theone or more metal lignosulfonates or metal salts comprise iron, ironoxides, cobalt, cobalt oxides, nickel, nickel oxides, or a combinationof them.

In another aspect, the present invention provides a method forseparating a liquid hydrocarbon material dispersed in a volume of water.In one embodiment, the method includes the steps of:

mixing a plurality of magnetic carbon-metal nanocomposites with a liquidhydrocarbon material dispersed in a volume of water to allow theplurality of magnetic carbon-metal nanocomposites each to be adhered byan amount of the liquid hydrocarbon material to form a mixture;

applying a magnetic force to the mixture to attract the plurality ofmagnetic carbon-metal nanocomposites each adhered by an amount of theliquid hydrocarbon material;

removing said plurality of magnetic carbon-metal nanocomposites eachadhered by an amount of the liquid hydrocarbon material from said volumeof water while maintaining the applied magnetic force;

removing the magnetic force; and

separating the liquid hydrocarbon material from the said plurality ofmagnetic carbon-metal nanocomposites,

wherein the plurality of magnetic carbon-metal nanocomposites is formedby subjecting one or more metal lignosulfonates or metal salts tomicrowave radiation, in presence of lignin/derivatives either inpresence of alkali or a microwave absorbing material, for a period oftime effective to allow a plurality of carbon-metal nanocomposites to beformed.

In yet another aspect, the present invention provides a method forseparating a liquid hydrocarbon material from a body of water. In oneembodiment, the method includes the steps of:

mixing a plurality of magnetic carbon-metal nanocomposites with a liquidhydrocarbon material dispersed in a body of water to allow the pluralityof magnetic carbon-metal nanocomposites each to be adhered by an amountof the liquid hydrocarbon material to form a mixture;

applying a magnetic force to the mixture to attract the plurality ofmagnetic carbon-metal nanocomposites each adhered by an amount of theliquid hydrocarbon material; and

removing said body of water from said plurality of magnetic carbon-metalnanocomposites each adhered by an amount of the liquid hydrocarbonmaterial while maintaining the applied magnetic force,

wherein the plurality of magnetic carbon-metal nanocomposites is formedby subjecting one or more metal lignosulfonates or metal salts tomicrowave radiation, in presence of lignin/derivatives either inpresence of alkali or a microwave absorbing material, for a period oftime effective to allow a plurality of carbon-metal nanocomposites to beformed.

These and other aspects of the present invention will become apparentfrom the following description of the preferred embodiment taken inconjunction with the following drawings and their captions, althoughvariations and modifications therein may be affected without departingfrom the spirit and scope of the novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described below are for illustration purposes only. Thedrawings are not intended to limit the scope of the present teachings inany way. The patent or application file may contain at least one drawingexecuted in color. If so, copies of this patent or patent applicationpublication with color drawing(s) will be provided by the Office uponrequest and payment of the necessary fee.

FIG. 1 shows a typical sulfonated/sulfomethylated lignin monomer unitrelated to various embodiments of the present invention.

FIG. 2 shows a reaction scheme for the sulfonation of a monomeric unitof a condensed tannin according to various embodiments of the presentinvention.

FIG. 3 shows an SEM image of nickel nanoparticles embedded in a carbonmatrix prepared from nickel lignosulfonate using the microwave techniqueaccording to one embodiments of the present invention.

FIG. 4 shows a Raman spectroscopy of a microwave generated carbonaccording to one embodiments of the present invention.

DETAILED DESCRIPTION

The present invention is more particularly described in the followingexamples that are intended as illustrative only since numerousmodifications and variations therein will be apparent to those skilledin the art. Various embodiments of the invention are now described indetail. Referring to the drawings, FIGS. 1-4, like numbers, if any,indicate like components throughout the views. As used in thedescription herein and throughout the claims that follow, the meaning of“a”, “an”, and “the” includes plural reference unless the contextclearly dictates otherwise. Also, as used in the description herein andthroughout the claims that follow, the meaning of “in” includes “in” and“on” unless the context clearly dictates otherwise. Moreover, titles orsubtitles may be used in the specification for the convenience of areader, which shall have no influence on the scope of the presentinvention. Additionally, some terms used in this specification are morespecifically defined below.

DEFINITIONS

The terms used in this specification generally have their ordinarymeanings in the art, within the context of the invention, and in thespecific context where each term is used. Certain terms that are used todescribe the invention are discussed below, or elsewhere in thespecification, to provide additional guidance to the practitionerregarding the description of the invention. For convenience, certainterms may be highlighted, for example using italics and/or quotationmarks. The use of highlighting has no influence on the scope and meaningof a term; the scope and meaning of a term is the same, in the samecontext, whether or not it is highlighted. It will be appreciated thatsame thing can be said in more than one way. Consequently, alternativelanguage and synonyms may be used for any one or more of the termsdiscussed herein, nor is any special significance to be placed uponwhether or not a term is elaborated or discussed herein. Synonyms forcertain terms are provided. A recital of one or more synonyms does notexclude the use of other synonyms. The use of examples anywhere in thisspecification including examples of any terms discussed herein isillustrative only, and in no way limits the scope and meaning of theinvention or of any exemplified term. Likewise, the invention is notlimited to various embodiments given in this specification.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention pertains. In the case of conflict, thepresent document, including definitions will control.

As used herein, “around”, “about” or “approximately” shall generallymean within 20 percent, preferably within 10 percent, and morepreferably within 5 percent of a given value or range. Numericalquantities given herein are approximate, meaning that the term “around”,“about” or “approximately” can be inferred if not expressly stated.

As used herein, the term “scanning electron microscope (SEM)” refers toa type of electron microscope that images the sample surface by scanningit with a high-energy beam of electrons in a raster scan pattern. Theelectrons interact with the atoms that make up the sample producingsignals that contain information about the sample's surface topography,composition and other properties such as electrical conductivity.

As used herein, the term “X-ray diffraction (XRD)” refers to one ofX-ray scattering techniques that are a family of non-destructiveanalytical techniques which reveal information about thecrystallographic structure, chemical composition, and physicalproperties of materials and thin films. These techniques are based onobserving the scattered intensity of an X-ray beam hitting a sample as afunction of incident and scattered angle, polarization, and wavelengthor energy. In particular, X-ray diffraction finds the geometry or shapeof a molecule, compound, or material using X-rays. X-ray diffractiontechniques are based on the elastic scattering of X-rays from structuresthat have long range order. The most comprehensive description ofscattering from crystals is given by the dynamical theory ofdiffraction.

As used herein, the term “Raman spectroscopy” or “Raman technique”refers to an optical technique that probes the specific molecularcontent of a sample by collecting in-elastically scattered light. Asphotons propagate through a medium, they undergo both absorptive andscattering events. In absorption, the energy of the photons iscompletely transferred to the material, allowing either heat transfer(internal conversion) or re-emission phenomena such as fluorescence andphosphorescence to occur. Scattering, however, is normally an in-elasticprocess, in which the incident photons retain their energy. In Ramanscattering, the photons either donate or acquire energy from the medium,on a molecular level. In contrast to fluorescence, where the energytransfers are on the order of the electronic bandgaps, the energytransfers associated with Raman scattering are on the order of thevibrational modes of the molecule. These vibrational modes aremolecularly specific, giving every molecule a unique Raman spectralsignature.

Raman scattering is a very weak phenomena, and therefore practicalmeasurement of Raman spectra of a medium requires high power excitationlaser sources and extremely sensitive detection hardware. Even withthese components, the Raman spectra from tissue are masked by therelatively intense tissue auto-fluorescence. After detection, postprocessing techniques are required to subtract the fluorescentbackground and enable accurate visualization of the Raman spectra. Ramanspectra are plotted as a function of frequency shift in units ofwavenumber (cm⁻¹). The region of the Raman spectra where most biologicalmolecules have Raman peaks is from 500 to 2000 cm⁻¹. In contrast tofluorescence spectra, Raman spectra have sharp spectral features thatenable easier identification of the constituent sources of spectralpeaks in a complex sample.

As used herein, “nanoscopic-scale,” “nanoscopic,” “nanometer-scale,”“nanoscale,” “nanocomposites,” “nanoparticles,” the “nano-” prefix, andthe like generally refers to elements or articles having widths ordiameters of less than about 1 μm, preferably less than about 100 nm insome cases. In all embodiments, specified widths can be smallest width(i.e. a width as specified where, at that location, the article can havea larger width in a different dimension), or largest width (i.e. where,at that location, the article's width is no wider than as specified, butcan have a length that is greater).

As used herein, “plurality” means two or more.

As used herein, the terms “comprising,” “including,” “carrying,”“having,” “containing,” “involving,” and the like are to be understoodto be open-ended, i.e., to mean including but not limited to.

OVERVIEW OF THE INVENTION

The present invention provides, among other things, a method forsynthesis, and use of a material derived from renewable resources thatis quick, efficient and highly effective in separating oil from water.The oil could be any hydrophobic material that would be attracted tocarbon and includes major oil spills such as that resulting from oiltanker disasters and such. The material is made by the microwavetreatment of metal lignosulfonates or metal salts in presencelignin/derivatives either in presence of alkali or a microwave absorbingmaterial such as graphite, carbon black etc. The microwave used could bea domestic kitchen microwave and does not require significantinvestment. The metals used are those that are magnetic in theirelemental form or in their oxide form. Examples of such metals includeiron, cobalt and nickel.

Thus, in one aspect, the present invention provides a method forseparating a liquid hydrocarbon material from a body of water. In oneembodiment, the method includes the steps of:

mixing a plurality of magnetic carbon-metal nanocomposites with a liquidhydrocarbon material dispersed in a body of water to allow the pluralityof magnetic carbon-metal nanocomposites each to be adhered by an amountof the liquid hydrocarbon material to form a mixture;

applying a magnetic force to the mixture to attract the plurality ofmagnetic carbon-metal nanocomposites each adhered by an amount of theliquid hydrocarbon material; and

removing said plurality of magnetic carbon-metal nanocomposites eachadhered by an amount of the liquid hydrocarbon material from said bodyof water while maintaining the applied magnetic force,

wherein the plurality of magnetic carbon-metal nanocomposites is formedby subjecting one or more metal lignosulfonates or metal salts tomicrowave radiation, in presence of lignin/derivatives either inpresence of alkali or a microwave absorbing material, for a period oftime effective to allow a plurality of carbon-metal nanocomposites to beformed.

In one embodiment, the microwave radiation has a frequency in the rangeof 900 MHz to 5.8 GHz.

In one embodiment, the microwave absorbing material comprises graphite,carbon black, or a combination of them.

The one or more metal lignosulfonates or metal salts each are magneticin their elemental form or in their oxide form. In one embodiment, theone or more metal lignosulfonates or metal salts comprise iron, ironoxides, cobalt, cobalt oxides, nickel, nickel oxides, or a combinationof them.

The steps set forth above can be repeated for one or more times withrespect to said body of water until the quality of water reaches adesired level. The liquid hydrocarbon material can be recovered from theremoved plurality of magnetic carbon-metal nanocomposites each adheredby an amount of the liquid hydrocarbon material after the magnetic forceis removed.

In another aspect, the present invention provides a method forseparating a liquid hydrocarbon material dispersed in a volume of water.In one embodiment, the method includes the steps of:

mixing a plurality of magnetic carbon-metal nanocomposites with a liquidhydrocarbon material dispersed in a volume of water to allow theplurality of magnetic carbon-metal nanocomposites each to be adhered byan amount of the liquid hydrocarbon material to form a mixture;

applying a magnetic force to the mixture to attract the plurality ofmagnetic carbon-metal nanocomposites each adhered by an amount of theliquid hydrocarbon material;

removing said plurality of magnetic carbon-metal nanocomposites eachadhered by an amount of the liquid hydrocarbon material from said volumeof water while maintaining the applied magnetic force;

removing the magnetic force; and

separating the liquid hydrocarbon material from the said plurality ofmagnetic carbon-metal nanocomposites,

wherein the plurality of magnetic carbon-metal nanocomposites is formedby subjecting one or more metal lignosulfonates or metal salts tomicrowave radiation, in presence of lignin/derivatives either inpresence of alkali or a microwave absorbing material, for a period oftime effective to allow a plurality of carbon-metal nanocomposites to beformed.

In one embodiment, the microwave radiation has a frequency in the rangeof 900 MHz to 5.8 GHz.

In one embodiment, the microwave absorbing material comprises graphite,carbon black, or a combination of them.

The one or more metal lignosulfonates or metal salts each are magneticin their elemental form or in their oxide form. In one embodiment, theone or more metal lignosulfonates or metal salts comprise iron, ironoxides, cobalt, cobalt oxides, nickel, nickel oxides, or a combinationof them.

In yet another aspect, the present invention provides a method forseparating a liquid hydrocarbon material from a body of water. In oneembodiment, the method includes the steps of:

mixing a plurality of magnetic carbon-metal nanocomposites with a liquidhydrocarbon material dispersed in a body of water to allow the pluralityof magnetic carbon-metal nanocomposites each to be adhered by an amountof the liquid hydrocarbon material to form a mixture;

applying a magnetic force to the mixture to attract the plurality ofmagnetic carbon-metal nanocomposites each adhered by an amount of theliquid hydrocarbon material; and

removing said body of water from said plurality of magnetic carbon-metalnanocomposites each adhered by an amount of the liquid hydrocarbonmaterial while maintaining the applied magnetic force,

wherein the plurality of magnetic carbon-metal nanocomposites is formedby subjecting one or more metal lignosulfonates or metal salts tomicrowave radiation, in presence of lignin/derivatives either inpresence of alkali or a microwave absorbing material, for a period oftime effective to allow a plurality of carbon-metal nanocomposites to beformed.

In one embodiment, the microwave radiation has a frequency in the rangeof 900 MHz to 5.8 GHz.

In one embodiment, the microwave absorbing material comprises graphite,carbon black, or a combination of them.

The one or more metal lignosulfonates or metal salts each are magneticin their elemental form or in their oxide form. In one embodiment, theone or more metal lignosulfonates or metal salts comprise iron, ironoxides, cobalt, cobalt oxides, nickel, nickel oxides, or a combinationof them.

In one embodiment, the method further comprises the steps of introducingsaid body of water to a second container, and repeating the steps setforth immediately above to said body of water.

The steps set forth above can be further repeated for one or more timeswith respect to said body of water until the quality of water reaches adesired level. The liquid hydrocarbon material can be recovered from theplurality of magnetic carbon-metal nanocomposites each adhered by anamount of the liquid hydrocarbon material after the magnetic force isremoved.

Additional details are set forth below.

EXAMPLES

Aspects of the present teachings may be further understood in light ofthe following examples, which should not be construed as limiting thescope of the present teachings in any way.

Example 1

Lignin and Sources.

Lignin, the major non-cellulosic constituent of wood, is a complexphenolic polymer that bears a superficial resemblance tophenol-formaldehyde resins. It consists of functionalized phenylpropaneunits connected via alkyl and aryl ether linkages. Essentially, all ofthe lignin commercially available is isolated as by-products from thepaper industry from either the sulfite or the Kraft process.

Sulfonated lignins are obtained either as spent sulfite liquor (SSL) orby sulfonation of lignin obtained from the Kraft process. SSL obtainedfrom the sulfite process consists of lignosulfonates (˜55%), sugars(30%), and other ingredients in smaller amounts. FIG. 1 shows a typicalmonomeric unit of Kraft lignin that has been sulfomethylated at thearomatic ring and sulfonated on the aliphatic side chain.Sulfomethylation is accomplished by the reaction of the Kraft ligninwith formaldehyde and sodium sulfite. The aliphatic sulfonation occurspreferentially at the benzylic position of the side chain of thephenylpropane units. Lignosulfonates are available in the form ofcalcium or sodium salts (Borasperse® and Ultrazine® from Mead Westvaco,for examples) and are cheaper alternatives to other forms oflignosulfonates. Lignotech's calcium salt of lignosulfonic acid[Borresperse-CA] is especially suitable for the synthesis ofmetal-carbon nanocomposites. Some of the applications of lignosulfonatesare in concrete admixtures, animal feed, oil-well drilling muds, dustcontrol, emulsion stabilizers, dye dispersants, wood preservation, andmining aids. Almost a million metric tones of lignosulfonate is producedevery year and the major manufacturers and their annual production ispublished.

Mead Westvaco and LignoTech USA are two of the major manufacturers oflignosulfonates in the U.S. and a variety of sulfonated lignin productsare available from them. The sulfonation can be controlled to occureither at the aromatic ring or the benzylic position or both. The degreeand position of sulfonation can affect the final property and potentialapplication of the lignin.

Example 2

Tannin and Sources.

Tannins are naturally occurring polyphenols that are found in thevascular tissue of plants such as the leaves, bark, grasses, andflowers. They are classified into two groups: condensed tannins andhydrolysable tannins FIG. 2 illustrates the reaction scheme for thesulfonation of monomeric unit of a condensed tannin. The structureconsists of three rings: two benzene rings on either side of anoxygen-containing heterocyclic ring. The A-ring to the left of thecyclic ether ring consists of one or two hydroxyl groups. The B-ringpresent on the right of the cyclic ether ring also consists of two orthree hydroxyl groups.

A particular tannin of interest is Quebracho tannin. This tannin isobtained from the hot water extraction of the heartwoods of Schinopsisbalansae and lorentzii, indigenous to Argentina and Paraguay. Quebrachoaccounts for 30% of the dry weight of the heartwoods with a productionlevel averaging 177,000 tons per year over the past 30 years, accordingto the Tannin Corporation, Peabody, Mass. Sulfonated tannins arecommercially available and represent an inexpensive renewable resource.For example, Chevron Philips Company in Bartlesville, Okla. suppliestannins with different degrees of sulfonation. The MSDSs and technicaldata sheets providing the structure and percentage of sulfur in theproducts are also provided. Sold under the trade name of “Orform”tannins, these represent an alternate source of a sulfonated renewableresource that could be compared to sulfonated lignins.

Example 3

Synthesis of Carbon Nanostructures and Carbon-Metal Nanocomposites.

In a typical preparation of carbon particles from lignin, tannin,lignosulfonate or tanninsulfonate or mixtures thereof according to oneembodiment of the present invention, a one gram sample of the woodbyproduct is treated with four drops of 85% phosphoric acid and mixedthoroughly using a mortar and pestle. It is then placed in a test tubeand placed vertically inside a beaker inside a microwave-oven under thehood. The oven is then turned on for a duration of 4 minutes. The samplesparks and then turns red, glowing during the entire process. The samplemay then be optionally heated further or the reaction may be terminated.The black sample is then powdered using a mortar and pestle and thenintroduced in an Erlenmeyer flask. A 100 mL aliquot of deionized (DI)water is brought to boil while stirring. The solution is then cooled toroom temperature and filtered through a coarse filter paper. Residue iswashed with 4×100 mL of DI water and then dried on the filter paper viasuction. It is then dried further in a vacuum oven at room temperatureovernight.

In a typical preparation of carbon-metal nanocomposites according to oneembodiment of the present invention, the lignosulfonate sodium salt isconverted to the desired metal lignosulfonate salt prior tocarbonization.

A 10 g sample of calcium lignosulfonate according to one embodiment ofthe present invention, which has 5% Ca²⁺ (0.0125 mol Ca ions) is addedto 70 mL of DI water and heated to 90 degrees C. with stirring. A 0.0125mol sample of metal sulfate (cobalt, nickel, iron, etc.) is then addedto the solution and the reaction mixture heated for one hour at 90degrees C. The solution is then cooled and filtered through a coarsefilter paper and the filtrate is then heated at 85 degrees C. until thewater evaporates. It is then furthered dried in a vacuum oven overnightat room temperature. Typical yield is around 85-90%. (Instead of thecalcium salt, sodium salts in presence of metal salts may be used astarting materials for the preparation of carbon-metal nanocomposites.)

In case of metal lignosulfonates according to one embodiment of thepresent invention, a 1 g sample is treated with 4 drops of 85%phosphoric acid and thoroughly mixed using a mortar and pestle. It isthen subjected to microwave radiation using a 650 Watt microwave ovenplaced under a hood for 2 minutes. It is then subjected to further 4minutes of microwave treatment. The sample is cooled and introduced intoa mortar and pestle and powdered. The sample is treated in boiling waterfor 10 minutes and cooled and filtered through suction. It is thenwashed with 4×100 mL of DI water and dried on the filter paper undersuction. It is further dried in a vacuum oven in room temperatureovernight.

In another method according to one embodiment of the present inventionalkali is added to convert the metal lignosulfonate to a metal oxidewhich becomes an excellent microwave absorber. The heat generated issufficient to carbonize the lignin and to make metal in the zero valentstate by reaction with carbon.

Example 4

Characterization of Nanomaterials.

The materials synthesized according to various embodiments of thepresent invention were characterized by Raman and SEM techniques.

As shown in FIG. 3, a Scanning Electron Microscope (SEM) image showsNickel nanoparticles embedded in a carbon matrix, which are preparedfrom Nickel lignosulfonate using the microwave technique according toone embodiment of the present invention.

A typical Raman spectroscopic data of a microwave generated carbon thatis made according to one embodiment of the present invention is plottedin FIG. 4. In Raman spectroscopy as shown in FIG. 4, the peak at 1580cm⁻¹ that represents the G-band (graphite) represents the E_(2g) mode(stretching mode) related to the sp² carbons. The diffuse band (D-band)that occurs around 1360 cm⁻¹ represents the A_(1g) mode (breathingmode), and is associated with C atoms in a disordered or glassy state.The measure of I_(G)/I_(D) intensity ratio is generally used as ameasure of graphite ordering. The broad peak that shows a maximum around2700 cm⁻¹ is ascribed to the first overtone of the D band.

Example 5

Synthesis of Carbon-Iron Composite.

Another preparation of carbon particles from iron lignosulfonate usinggraphite to initiate the microwave assisted carbonization was carriedout in a synthesis process similar to that of EXAMPLE 3 according to oneembodiment of the present invention. The material obtained from theprocess was found to be magnetic as demonstrated by its attraction to anordinary bar magnet, which is a collection of magnetic carbon-ironnanocomposites.

Example 6

Use of Magnetic Carbon-Iron Nanocomposites for Oil Spill Clean Up andRecovery.

A 0.3 gram sample of magnetic carbon-iron nanocomposites made accordingto an examplary process of EXAMPLE 5 was added to a liquid mixture in acontainer containing 50 mL of water and 1 mL of toluene, and then gentlymixed with a glass rod. The sample of magnetic carbon-ironnanocomposites adhered to the toluene, which then was removed using astrong magnet from the water. Only traces of toluene could be seen leftin the water. The water having traces of toluene can be treated againwith another sample of magnetic carbon-iron nanocomposites in the samecontainer or another container, which would further clean the water.Additional one or more similar treatments can be performed till thequality of water reaches a desired level. The removed toluene could berecovered from the magnetic carbon-iron nanocomposites adhered to thetoluene after the magnetic force is removed.

Example 7

Use of Magnetic Carbon-Iron Nanocomposites for Oil Spill Clean Up andRecovery.

In another practice of the present invention, a 0.3 gram sample ofmagnetic carbon-iron nanocomposites made according to an exemplaryprocess of EXAMPLE 5 was added to a liquid mixture in a containercontaining 50 mL of water and 1 mL of mineral oil, and then gently mixedwith a glass rod. The sample of magnetic carbon-iron nanocompositesadhered to the mineral oil, which then was removed using a strong magnetfrom the water. Only traces of mineral oil could be seen left in thewater. The water having traces of mineral oil can be treated again withanother sample of magnetic carbon-iron nanocomposites in the samecontainer or another container, which would further clean the water.Additional one or more similar treatments can be performed till thequality of water reaches a desired level. The removed mineral oil couldbe recovered from the magnetic carbon-iron nanocomposites adhered to themineral oil after the magnetic force is removed.

The foregoing description of the exemplary embodiments of the inventionhas been presented only for the purposes of illustration and descriptionand is not intended to be exhaustive or to limit the invention to theprecise forms disclosed. Many modifications and variations are possiblein light of the above teaching.

The embodiments were chosen and described in order to explain theprinciples of the invention and their practical application so as toenable others skilled in the art to utilize the invention and variousembodiments and with various modifications as are suited to theparticular use contemplated. Alternative embodiments will becomeapparent to those skilled in the art to which the present inventionpertains without departing from its spirit and scope. Accordingly, thescope of the present invention is defined by the appended claims ratherthan the foregoing description and the exemplary embodiments describedtherein.

What is claimed is:
 1. A method of separating a liquid hydrocarbonmaterial from a body of water, comprising the steps of: (a) mixingpredetermined amount of pre-prepared magnetic carbon-metalnanocomposites with a liquid hydrocarbon material dispersed in a body ofwater to allow the pre-prepared magnetic carbon-metal nanocompositeseach to be adhered by an amount of the liquid hydrocarbon material toform a mixture; (b) applying a magnetic force to the mixture to attractthe magnetic carbon-metal nanocomposites each adhered by an amount ofthe liquid hydrocarbon material; and (c) removing said magneticcarbon-metal nanocomposites each adhered by an amount of the liquidhydrocarbon material from said body of water while maintaining theapplied magnetic force, wherein the magnetic carbon-metal nanocompositeseach include metal nanoparticles embedded in a carbon matrix; andwherein a substantial amount of carbon in the predetermined amount ofpre-prepared magnetic carbon-metal nanocomposites has a first peak at1587 cm⁻¹ and a second peak at 1330 cm⁻¹ or a first peak at 1590 cm⁻¹and a second peak at 1330 cm⁻¹ in Raman spectroscopy.
 2. The method ofclaim 1, further comprising repeating the steps (a)-(c) to said body ofwater.
 3. The method of claim 1, wherein the predetermined amount ofpre-prepared magnetic carbon-metal nanocomposites are formed bysubjecting a first metal lignosulfonate to microwave radiation.
 4. Themethod of claim 3, wherein the microwave radiation has a frequency inthe range of 900 MHz to 5.8 GHz.
 5. The method of claim 3, wherein thefirst metal lignosulfonate is formed by mixing a second metallignosulfonate and a metal salt and then heating the mixture.
 6. Themethod of claim 5, wherein the metal salt comprises iron.
 7. The methodof claim 3, wherein the first metal lignosulfonate is formed by mixing alignin or a lignin derivative with a metal salt and then heating themixture.
 8. The method of claim 3, wherein the first metallignosulfonate is alkali treated before subjecting the first metallignosulfonate to microwave radiation.
 9. The method of claim 3, whereina microwave absorbing material is added to the first metallignosulfonate before subjecting the first metal lignosulfonate tomicrowave radiation.
 10. The method of claim 9, wherein the microwaveabsorbing material comprises graphite.
 11. The method of claim 1,wherein the carbon-metal nanocomposites include iron nanoparticles inelemental state.
 12. A method of separating a liquid hydrocarbonmaterial dispersed in a volume of water, comprising the steps of: (a)mixing a predetermined amount of pre-prepared magnetic carbon-metalnanocomposites with a liquid hydrocarbon material dispersed in a volumeof water to allow the pre-prepared magnetic carbon-metal nanocompositeseach to be adhered by an amount of the liquid hydrocarbon material toform a mixture; (b) applying a magnetic force to the mixture to attractthe magnetic carbon-metal nanocomposites each adhered by an amount ofthe liquid hydrocarbon material; (c) removing said magnetic carbon-metalnanocomposites each adhered by an amount of the liquid hydrocarbonmaterial from said volume of water while maintaining the appliedmagnetic force; (d) removing the magnetic force; and (e) separating theliquid hydrocarbon material from the said magnetic carbon-metalnanocomposites, wherein the pre-prepared magnetic carbon-metalnanocomposites each include metal nanoparticles embedded in a carbonmatrix; and wherein a substantial amount of carbon in the predeterminedamount of pre-prepared magnetic carbon-metal nanocomposites has a firstpeak at 1587 cm⁻¹ and a second peak at 1330 cm⁻¹ or a first peak at 1590cm⁻¹ and a second peak at 1330 cm⁻¹ in Raman spectroscopy.
 13. Themethod of claim 12, wherein the predetermined amount of pre-preparedmagnetic carbon-metal nanocomposites are formed by subjecting a firstmetal lignosulfonate to microwave radiation.
 14. The method of claim 13,wherein the microwave radiation has a frequency in the range of 900 MHzto 5.8 GHz.
 15. The method of claim 13, wherein the first metallignosulfonate is formed by mixing a second metal lignosulfonate and ametal salt and then heating the mixture.
 16. The method of claim 15,wherein the first metal lignosulfonate is formed by mixing a lignin or alignin derivative with a metal salt and then heating the mixture. 17.The method of claim 16, wherein the metal salt comprises iron.
 18. Themethod of claim 13, wherein the first metal lignosulfonate is treatedwith alkali before subjecting the first metal lignosulfonate tomicrowave radiation.
 19. The method of claim 13, wherein a microwaveabsorbing material is added to the first metal lignosulfonate beforesubjecting the first metal lignosulfonate to microwave radiation. 20.The method of claim 19, wherein the microwave absorbing materialcomprises graphite.
 21. The method of claim 12, wherein the carbon-metalnanocomposite includes iron nanoparticles in elemental state.